Automobiles and, more specifically, race cars such as dragsters, funny cars and the like, that are designed for acceleration racing are typically operated at race tracks to determine their quickness within a given distance, e.g., within a quarter of a mile. Such cars are specially modified to produce high levels of horsepower to the rear wheels in an effort to minimize the time that it takes the car to cover such specified distance. Such cars are also often modified in other ways to minimize such time, e.g., by making the car body more aerodynamic to minimize air drag, and by minimizing the weight of the car.
Under conditions of maximum acceleration it is not uncommon for the front end and/or wheels of the car to be lifted away from the ground, thereby raising the center of gravity of the vehicle and making the car difficult or impossible to control. When this occurs, the driver must either discontinue his run, by letting off of the gas and/or activating the car brakes, or risk damaging the car and/or possibly injuring him or her self.
In an effort to control or reduce the amount of front end lift during conditions of maximum acceleration, lift control frame structures referred to as "wheelee bars" have been devised. Such frame structures 10 are typically of a triangular-shaped tubular construction as illustrated in FIG. 1 comprising: (1) a first mounting point 12 at one end of the triangle, that is connected to an upper portion of a rear part of the car chassis or rear suspension; (2) a second mounting point 14 at another end of the triangle, that is connected to one or more wheel 16 that is oriented to rotate when placed into contact with the ground; and (3) a third mounting point 18 at a final end of the triangle, that is connected to a lower portion of the rear part of the car chassis or rear suspension. The first, second and third mounting points are connected by frame members 20 and 22, respectively. As illustrated in FIG. 1, such frame structure may include two such triangle constructions that each have separate first, second, and third mounting points, and that are attached together by tubular cross members and the like. It is to be understood that the frame structure illustrated in FIG. 1 is exemplary of but one type of lift control frame structure known to exist and that variations of such design may exist.
The lift control frame structure is attached at its first and third mounting point to the rear portion of the car so that the second mounting point extends a distance rearward of the rear end of the car, and so that the structure wheel extends a short distance away from the ground. Under conditions of maximum acceleration, as the front end of the car begins to be lifted upward, the second mounting point and wheel is moved toward the ground. As the front end of the car continues to be lifted upward, the wheel attached to the second mounting point makes contact with the ground, limiting the extend to which the front end of the car can be raised. However, in doing so the frame structure also acts to lift the rear chassis and/or suspension of the car, thereby reducing the load that is placed on the rear wheels. A reduction in the load on the rear wheels is not desired during operating conditions of maximum acceleration because it cases the rear wheels to slip and lose traction with the ground. This reduced traction prevents the car from achieving its maximum acceleration. When this happens during a race, the driver must either let off of the gas or try to control the engine output to regain traction. In either case, such occurrence usually results in car the losing the race.
It is, therefore, desirable, that a device be constructed to progressively control the amount of lift at the front end of a car during conditions of maximum acceleration without unloading the rear end of the car. It is also desirable that such a device be constructed in a manner that permits it to be used in conjunction with existing lift control frame structures.